1. Technical Field
The present invention relates to trayliners for use in a sterilization process and, more particularly, to a super-absorbent trayliner for cushioning surgical instruments and providing an advantageous moisture absorption functionality during and after completion of a sterilization process. In a preferred embodiment of the present invention, a super-absorbent, foam plastic trayliner is disclosed for cushioning surgical instruments and providing an advantageous moisture absorption functionality during and after sterilization procedures that utilize steam and/or ethylene oxide gas as a sterilization agent.
2. Background of the Related Art
As is well known, surgical instruments used in the healthcare industry must be sterilized before and after each use. Sterilization, of course, frees instruments from microorganism contamination, to prevent infections and the spread of diseases among patients. All medical procedures rely upon a stringent program of sterilization.
The medical device industry has addressed the sterilization requirements in the surgical field by offering two general types of surgical instruments: reusable instruments and single use, or disposable, instruments. Reusable instruments are typically composed of stainless steel and are typically sterilized before their initial use and then cleaned and resterilized prior to each subsequent use thereof. Single use or disposable instruments, on the other hand, are often fabricated primarily from plastic materials, thereby reducing costs associated with manufacture, and are discarded after use in a single procedure.
With respect to reusable surgical instruments, e.g., forceps, graspers, dissectors, probes, hemostats, scissors and the like, historically sterilization and resterilization have been accomplished using two primary sterilization modalities: steam sterilization and ethylene oxide sterilization. Of the two primary sterilization modalities, steam sterilization has been the overwhelmingly dominant method of sterilization in the surgical instrument field.
In a broad sense, the sterilization process generally involves placing instruments to be sterilized in a tray, wrapping the instruments and the tray with a sterilization wrap, and placing the wrapped tray and instruments in a sterilization chamber where the instruments are exposed to the sterilization medium of either steam or ethylene oxide. Preferably, the instruments are placed in a tray and wrapped before initiating exposure to the sterilization medium. Wrapping the tray generally contributes to providing a level of protection to the surgical instruments, e.g., during post-sterilization storage and handling prior to actual use, and to maintaining the instruments in a dry, sterile condition. Typically, sterilization trays are wrapped with a sterilization wrap, e.g., paper. Other instruments to be sterilized include basins. Basins are separated by cotton towels or other absorbent materials and then wrapped in sterilization wrap prior to sterilization.
One long and continuing problem encountered with steam and/or ethylene oxide sterilization, however, is the presence of moisture that remains on the implements such as on sterilized instruments, i.e., within the sterile wrap, at the conclusion of the sterilization process. This residual moisture can range from slight levels of dampness to visible droplets on the surface of surgical instruments. Such residual moisture is both undesirable and is unacceptable because such moisture could permit migration of surface microorganisms, thereby penetrating the wrapped tray and rendering its contents contaminated.
A wrapped tray with residual moisture has been termed a xe2x80x9cwet pack,xe2x80x9d i.e., a wrapped tray containing surgical instruments having surface moisture on the inside and/or outside of the wrapped tray, e.g., during and after the sterilization process. In one of its marketing publications, Getinge/Castle, Inc. of Rochester, N.Y., a major manufacturer of sterilizers, refers to the xe2x80x9cwet packxe2x80x9d problem as xe2x80x9can age old predicament.xe2x80x9d Wet pack problems may be caused and/or exacerbated by, e.g., the use of new sterilizers, boiler or plumbing changes or even ambient humidity variations due to air conditioning, etc. What is needed, therefore, is a more effective means than, e.g., a paper or cotton product for preventing the xe2x80x9cwet packxe2x80x9d problem and the resulting potential for contamination of sterilized surgical instruments.
According to the present invention, a highly absorbent trayliner is provided that may be advantageously placed in a sterilization tray, e.g., along the tray bottom, to absorb potential residual moisture generated during the sterilization process. The highly absorbent trayliner advantageously maintains surgical instruments positioned in the wrapped tray in a xe2x80x9cdryxe2x80x9d condition at the completion of the sterilization process and further cushions the instrumentation, thereby minimizing the potential for instrument damage during post-sterilization handling. The highly absorbent trayliner of the present invention is preferably compatible with a steam or ethylene oxide sterilization process.
In addition, the trayliner of the present invention advantageously neither interferes with nor inhibits conventional steam and ethylene oxide sterilization procedures. Thus, the super absorbent trayliner of the present invention permits air removal, sterilant penetration/evacuation, drying and effective aeration of instruments that are sterilized according to conventional steam or ethylene oxide sterilization procedures. Moreover, the instrument trayliner of the present invention is advantageously lint-free, preferably pre-cut to fit standard sterilization trays or other surgical instruments, and relatively inexpensive such that disposal of the trayliner after a single use is cost effective for sterilization operators.
The super-absorbent sterilization trayliner may be advantageously utilized in a sterilization method to achieve superior results, particularly in terms of reduced residual moisture on the surface(s) of surgical instrument(s). A sterilization method according to the present invention generally includes placing a trayliner in the bottom of a sterilization tray, placing one or more instruments on top of the trayliner, wrapping the tray in a sterilization wrap to form a pack, and then sterilizing the pack with steam or ethylene oxide.
In a preferred embodiment of the present invention, a super-absorbent trayliner is fabricated from a material that is moisture absorbent, i.e., hydrophilic, and preferably a material that absorbs moisture up to about thirty percent (30%) of its weight. Trayliners fabricated from materials having moisture absorbency at a level as described herein have been found to achieve beneficial results, e.g., prevent residual moisture on instrument surfaces post-sterilization, and allow effective operation of conventional steam and ethylene oxide processes. A preferred material for use in fabricating a super-absorbent trayliner according to the present invention is a hydrophilic polyurethane foam available from Foamex International, Inc. (Linwood, PA) under the tradename Aquazone(copyright).